The Red Line was the first line of the Delhi Metro to be constructed and opened. The Tis Hazari – Shahdara section of the line was inaugurated by the then Prime Minister of India, Shri. Atal Bihari Vajpayee, on 25 December 2002 and opened to the public on the same day.[9] Subsequent sections opened between Tis Hazari – Inderlok on 3 October 2003, Inderlok – Rithala on 31 March 2004 and Shahdara – Dilshad Garden on 4 June 2008.[10]
Phase III
As part of the Phase III of Delhi Metro, an eastward extension of 9.5 km from Dilshad Garden to Ghaziabad ISBT (New Bus Adda) was approved by DMRC and MoHUA in January 2014. Construction began in early 2015 and commercial operations started on 8 March 2019, thereby providing commuters another link to travel to Ghaziabad along with the Blue Line branch that connects to Kaushambi and Vaishali.[11] In November 2022, Delhi Metro introduced a set of two eight-coach trains on its Red Line, which were converted from the existing fleet of 39 six-coach trains.[12]
Phase IV
Under the Phase IV of the Delhi Metro, the Red Line is proposed to be extended towards Kundli with 21 new stations at Rohini Sector 25, Rohini Sector 26, Rohini Sector 31, Rohini Sector 32, Rohini Sector 36, Barwala, Rohini Sector 35, Rohini Sector 34, Bawana Industrial Area – 1 Sector 3,4, Bawana Industrial Area – 1 Sector 1,2, Bawana JJ Colony, Sanoth, New Sanoth, Depot Station, Bhorgarh Village, Anaj Mandi Narela, Narela DDA Sports Complex, Narela, Narela Sector 5, Kundli and Nathupur. All these stations will be elevated, except Depot Station, which would be at-grade.[13][14]